An ECB-LCD is a liquid crystal display electrically controlling the birefringence of a liquid crystal, and, according to the related art, is formed as a translucent reflective type unit including a transmitting unit and a reflecting unit. The transmitting unit is configured such that a screen may be seen using a backlight in dark environments, while the reflecting unit is configured such that a screen may be seen using external light in bright environments.
The translucent reflective type LCD as described above is configured such that light moves through the same light path in both a transmitting mode and a reflecting mode. To this end, an achromatic quarter wave film (AQWF) is attached between a liquid crystal panel and a polarizing plate. In this case, the achromatic quarter wave film may be formed by combining two retardation films having different phase difference values and optical axes, and the two retardation films are attached to each other such that the optical axes thereof form an angle of approximately 30° to 80°.
However, in the case of an ECB-LCD according to the related art, the retardation film attached to a polarizing plate disposed towards a light source and the retardation film attached to a polarizing plate disposed towards a viewer may respectively form different angles, and an angle between the retardation films may be very large. Therefore, when the polarizing plate is manufactured by being formed as a single plate, defects, resulting in a large loss rate of the films, a high fault rate due to a complicated manufacturing process, and high manufacturing costs have been caused.
In the related art, retardation films are generally manufactured such that the optical axes thereof are directed in a vertical direction, and each retardation film is cut at an angle formed by a polarizing plate and the optical axis of the retardation film. The cut retardation films are combined to be manufactured. For example, when a first retardation film (λ/2) forms an angle of 15° and a second retardation film (λ/4) forms an angle of 75°, with respect to an absorption axis of a polarizing plate, the two films are cut such that the optical axes thereof respectively form angles of 15° and 75° with respect to the absorption axis of the polarizing plate. In this case, since the cutting angles, with respect to the absorption axis of the polarizing plate, are respectively 15° and 75°, a large loss rate of the films may be generated, thereby causing an increase in raw material expenses and manufacturing costs.